The present invention relates to a flexible shaft assembly whose distal end can be controllably deflected (or steered) by a control member located at the assembly's proximal end. Embodiments of the invention find utility in medical applications, e.g., as endoscopes and catheters, and in industrial applications, e.g., as endoscopes and various articulated mechanisms.
In a preferred embodiment of the invention, the flexible shaft assembly is configured for use as a medical endoscope incorporating illumination and imaging fibers, and a working lumen all extending from its proximal to its distal end, and all capable of being contained within a very small outside diameter, e.g. on the order of 3.0 mm or less. Such configurations are useful for example, as ureteroscopes, hysteroscopes, angioscopes, choledochoscopes, and cystoscopes.
The prior art is replete with flexible shaft endoscopes which incorporate a distal end which can be deflected by a user via a control member located at the shaft's proximal end. Such endoscopes are characterized by various shaft configurations which, for example, may make use of a multiplicity of vertebrated annuli or a tube with a series of transverse slots, configured to establish a moment of inertia profile which enhances the propensity of the shaft's distal end to bend in a controlled fashion in a defined plane. These shaft structures, by their nature, are complicated and costly to fabricate and are not particularly well suited for containment within very small outside diameters. The following patents are exemplary of deflectable shaft endoscopes:
______________________________________ 5,005,558 Aomori 4,919,112 Siegmund 4,911,148 Sosnowski 4,653,476 Bonnet 4,580,551 Siegmund 4,577,621 Patel 4,534,339 Collins 4,353,358 Emerson 3,788,304 Takahashi ______________________________________